diff --git a/default.nix b/default.nix
index bdab048245e21..8a03c3f838136 100644
--- a/default.nix
+++ b/default.nix
@@ -2,7 +2,7 @@ let
   requiredVersion = import ./lib/minver.nix;
 in
 
-if !builtins ? nixVersion || builtins.compareVersions requiredVersion builtins.nixVersion == 1 then
+if ! builtins ? nixVersion || builtins.compareVersions requiredVersion builtins.nixVersion == 1 then
 
   abort ''